12mhz kludge
Improved support for Arduino Due, Teensy 3, Gemma, Digispark

Teensy 3 (24, 48, 96 MHz), Arduino Due, DigiSpark (8, 16, 16.5 MHz), 12
MHz AVR devices. Inline AVR assembly code now works on both ATmega and
ATtiny; no more #ifdef house of cards.
Improved timing on Arduino Due

No more flicker!
Simplified Due code a little.
Add additional compatible product links
Add header guards
Merge pull request #5 from jrcutler/patch-1

Add additional compatible product links
Merge pull request #6 from jrcutler/patch-2

Add header guards
Added setBrightness() method
Fixed strandtest for 1m
Making Color utility function static
Merge pull request #7 from jrcutler/patch-1

Making Color utility function static
Changed setBrightness() behavior (scales pixel buffer contents)
Moved include guards
Fixed preprocessor check for AVR
Make "get" methods const
Added NeoPixel Rings goggles sketch
Changed gamma table in goggles sketch
Goggles: can change ring alignment, added ecto effect
Better inline asm syntax&format (no change in functionality)